I am: Astronomy I am: Orbit Who is? travel in a path Who is? More oval in shape around the Sun than perfectly circular I am: Rotate I am: Solar system Who is? An imaginary line Who is? Spins on an axis that runs through the middle of an object I am: An axis I am: Gravity Who is? Used to measure Who is? A force that keeps distances in the solar satellites in orbit system I am: An astronomical unit I am: A nebula Who is? A rotating cloud of Who is? Mercury, Venus, dust and gas Earth & Mars I am: The inner planets I am: A crater Who is? A bowl shaped depression that forms when The smallest inner an object crashes into a Who is? surface planet I am: Mercury I am: Venus Who is? The second planet Who is? The third planet from the Sun? from the Sun I am: Earth I am: Revolve Who is? The fourth planet Who is? The path made from the Sun? during a revolution around the Sun I am: Mars I am: Asteroids Who is? Small, rocky Who is? Beyond the objects that orbit the Sun asteroid belt I am: Elliptical I am: The outer planets Who is? The Sun and all it’s Who is? So large that all satellites other planets could fit in it I am: Jupiter I am: Saturn Who is? The second largest Who is? 4 times larger than planet in the solar system Earth? I am: Uranus I am: Comets Who is? Frozen chunks of Who is? Pieces of rock or ice, gas and dust metal in space, smaller than a few hundred meters I am: Meteoroids I am: Meteor Who is? Streak of light from Who is? Meteor that hits a burning meteoroid the Earth’s surface I am: Meteorite I am: Nuclear fusion Who is? A reaction in which Who is? Energy in the form of atoms fuse waves that can travel through space I am: Electromagnetic I am: Visible light radiation Who is? The distance Who is? Light that can be between crests on a wave seen I am: Wavelengths I am: Frequency Who is? The number of waves Who is? All the wavelengths of that pass through a given point the electromagnetic spectrum I am: Electromagnetic I am: Light year spectrum Who is? How bright a star The distance that Who is? appears light can travel in one year I am: Apparent magnitude I am: Absolute magnitude Who is? How bright a star Who is? A range of colors that actually is makes up light I am: Spectrum I am: H-R diagram Who is? Shows the Who is? A band of stars on relationship between star T the H-R diagram, ranging and absolute magnitude from Hot/blue/bright to Cool/red/dim I am: Main sequence I am: Protostar Who is? Gas & dust from a Who is? A star that has gone nebula pulled together by gravity through the main sequence, is now cooling and glowing red I am: Red giant I am: Planetary nebula Who is? A cloud around the Who is? A star that has core of a star collapsed and shines white hot I am: White dwarf I am: Black dwarf Who is? When all energy is gone Who is? The outer part of a star and a star has cooled explodes I am: Supernova I am: Neutron star Who is? Small, dense star Who is? An object so dense, about 10 km even light cannot escape I am: Black hole I am: Constellation Who is? A group of stars Who is? Two or more stars held named for a particular figure together by gravity or shape I am: Star system I am: Binary system Who is? Star system with two Who is? A large group of stars, stars gas, and dust held together by gravity I am: Galaxy I am: Spiral galaxy Who is? Have a bulge of old stars Who is? in the middles, arms containing dust, gas, young stars I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? I am: I am: Who is? Who is? .